Understanding The Major Causes Of AC Fan Motor Failure

Your air conditioning system is more than just a luxury — it's essential to maintaining a comfortable, productive environment. The AC fan motor is a big part of that, cooling air and keeping it moving throughout the space. It's also one of the most vulnerable components in an AC system since it constantly runs and has several moving parts.

However, when the fan motor fails, it can lead to discomfort, disruption, and unplanned repair costs. Understanding why this failure occurs and how to prevent it can make a big difference in ensuring your AC remains functional for years. Here are a few reasons why the AC fan motor might fail and what you can do about it.


When you fail to service your AC regularly, dirt and grime accumulate in the system, forming a layer of insulation. This layer reduces the heat exchange rate, and the motor has to work even harder to maintain the desired temperature. In doing so, it's subject to tremendous stress and can quickly overheat and burn out.

An overheating fan motor is difficult to miss if you're paying attention, as it becomes unusually hot and emits an unpleasant smell. It will also produce strange noises while running, especially when it's operating at low speeds.

The best way to avoid overheating is to keep the AC size appropriate to the space it's supposed to cool. Android-based air conditioner sizing-calculation apps are available, making it easier for homeowners to figure out the size that matches the house's cubic feet.

Making sure the condenser unit outside your house is also clean of any obstructions like tree leaves or overgrown shrubs will help too. It'll help the AC to draw in air from the outside more efficiently, reducing the load on the fan motor.

Voltage Surges and Fluctuations

A motor can fail if it's subject to large voltage surges and fluctuations due to an unstable power supply. This commonly happens when the electrical infrastructure is aging or faulty, resulting in damaging effects on appliance motors such as AC fans.

A sudden spike in electricity demand due to high usage or a power grid failure can cause an AC fan motor's voltage to soar, leading to immediate burnout. The motor's internal insulation may also be compromised due to long-term voltage fluctuations, leading to gradual damage and eventual failure.

To prevent this from happening, it's best to install a surge protector device that absorbs the excess electricity when such conditions arise. These are installed near your AC unit and work by sensing any unusual activity in the power supply and cutting it off.

If it's too late and your AC fan motor has already failed, don't worry. You only need to replace the motor itself and not the entire unit. Be sure to source a quality AC fan motor from an experienced supplier and hire a qualified repair expert so you don't have the same problems in the future. 

Reach out to a local air conditioning service provider to learn more.